Apparatus and method particularly suitable for use with closed loop color to color registration system of a web printing apparatus including a unique graphical user interface and register mark identification scheme.
It is known in the prior art to search out register mark patterns which reoccur.
Procedures useful in accomplishing this involve the identification of repetitive color marks as they appear in this recurring format. Techniques to date include determining and correlating position and color information for recurring elements in a repetitive pattern.
One such scheme searches out the existence of substantially identical dot pairs in each pattern and then their reoccurrence in subsequent patterns.
Further in prior art system interface schemes, technology has only advanced to the point of permitting the inputting of key parameters and related changes through the combined coordination of visual display and keyboard entries.
The function of a Color Register Control system on a printing press is to maintain close registration between colors printed on a surface by various printing cylinders. The control acquires an image of a cluster of register marks printed by various printing cylinders. The register mark is a geometrically unique mark. The mark cluster is acquired by the camera and each mark pattern is identified by checking shape of individual marks. Resulting location of a mark is used to compute and correct registration errors. The image is analyzed to identify marks printed by various printing cylinders. Register error is determined by computing the lateral and circumferential distance between marks printed by a print cylinder and a master print cylinder. Any error detected in this process is corrected by activating correction motors, typically stepper motors, on print cylinders.
The control utilizes a commercially available IBM-PC compatible computer, which can accept additional boards in the expansion slots.
A commercially available touch-screen monitor is utilized in a unique way for operator interface so as to accept operator commands and to display results utilizing only the touch-screen monitor.